Tumor Paints for real-time intraoperative visualization of solid tumors enable more complete resection while sparing surrounding normal tissue. For brain tumors this is of paramount importance, since removal of additional tissue can unnecessarily increase cognitive and functional impairment. The Tumor Paint CyTP007 is a peptide-fluorophore conjugate that specifically binds to multiple solid tumor types and fluoresces in the near-infrared range, minimizing light scatter and signal attenuation. Our overall long-term objectives are to determine the effective dose of CyTP007 for imaging during tumor resections (Phase 1), and to evaluate candidate intraoperative imaging devices (Phase 2). The proposed Phase 1 study is a dose-ranging study in dogs with solid tumors. Dogs undergoing tumor resection will receive CyTP007 intravenously 24 hours before surgery, and tissue will be imaged ex vivo after surgery. Specific aims: (1) Assess tolerability in the context of general anesthesia and surgery; (2) Determine optimal dose for imaging canine tumors; (3) Quantitate fluorescence in tumors; and (4) Assess specificity for cancer cells and signal-to-background ratio. Anticipated results include safety at an effective imaging dose; signal intensity in different tumor types; confirmation that CyTP007 penetrates the blood-brain barrier; and sensitivity and specificity for discrimination of cancer from normal cells.